1. Field of the Invention
This invention relates to a damper device for damping the opening and closing movement of a storage box installed in the interior of a car, and more particularly to a damper device in which a cylinder type air damper is provided with dustproof means.
2. Prior Art Statement
As damper devices for damping the opening and closing movement of a storage box which employ a cylinder type air damper and are installed in a car, there have heretofore been known damper devices for a glove compartments as disclosed, e.g., in Japanese Utility Model Public Disclosure No. Sho 61-11853. Also, as cylinder type air dampers which are provided with dustproof means, there have been known throttle valve devices as disclosed, e.g., in Japanese Utility Model Public Disclosure No. Sho 45-22600.
The first-mentioned damper device for a glove compartment employs a cylinder type air damper. However, its structure is not disclosed specifically.
In the second-mentioned throttle valve device, the cylinder member is threadedly engaged with a throttle screw having a cut-out groove, and the throttle screw is engaged with stationary nut which also serves as a cover for preventing the entrance of dust or the like.
Since the cylinder type air damper itself does not constitute any special feature in the first-mentioned damper device for a glove compartment, it is presumed that the air damper has an ordinary structure. Accordingly, when the glove compartment is opened or closed, especially when opened, a rod thereof is extended. As a result, external air is allowed to enter the cylinder member through a throttle valve. At that time, fine dust or the like floating in the car is drawn into the cylinder member together with air. This is particularly true, when the car is running. When the car is running, dust or the like can easily enter the car through open windows. Once in the car, such dust or the like drifts within the small, closed passenger compartment. Therefore, a large amount of dust or the like is apt to enter the cylinder member. The result is that the damping function is not effectively performed. Because of the foregoing, it is required that some effective means be established in order to prevent dust or the like from entering the cylinder member.
On the other hand, in the second-mentioned throttle valve device, since the stationary nut is formed such that it also acts as a cover, dust or the like is not allowed to accumulate in the space between the stationary nut and the throttle screw. However, since it is still designed such that external air is taken into the cylinder member, it is difficult to prevent the entrance of fine dust or the like included in ambient air into the cylinder member through the periphery of the throttle screw. As seen from the foregoing, the second-mentioned throttle valve device also has a shortcoming in that the damper function is adversely affected by the dust or the like entering the cylinder member.